This invention relates generally to an electronic timepiece operated on an internal battery and more particularly to a power circuit for a small thin electronic timepiece which operates reliably on a small battery. All circuits of a conventional electronic timepiece, such as the oscillator circuit, divider, display, alarm driving circuit and lamp driving circuit are connected simultaneously to the same power circuit for an electronic timepiece. When lighting the illumination lamp or driving the alarm circuit, especially at low temperature, battery voltage drops and failure of oscillation or erroneous circuit operation may result. For example, the count in the divider may become inaccurate. This reduced battery voltage can cause the timepiece to stop or their may be loss in time as displayed. To eliminate these defects in prior art timepieces having either or both an illumination lamp and an alarm, a large-sized and thick battery, having a low internal resistance, has been used. Accordingly, it has not been possible to provide a thin electronic timepiece with either or both an illumination lamp and an alarm.
What is needed is a power circuit for an electronic timepiece which provides reliable timekeeping operation in a thin electronic timepiece having either or both an illumination lamp and an alarm.